One of the major lacking features in the newest Office: no Metro applications. In fact, the only reason Windows RT has a desktop at all is because the Office team was unable to create Metro applications in time for the release of Windows RT. I often thought this was a classic case of two important divisions within Microsoft not getting along and not being aligned, but now that I have my own Surface RT, I'm starting to realise that there's a far simpler, and thus more likely, explanation: Metro is simply not ready for anything serious - or for anything at all, really.

One company which ought to know how to engineer well-performing stable Metro apps is Microsoft themselves. But according to the article, Microsoft's own apps are affected by performance and stability problems too.

History repeats itself!
Windows 1.0 was released on 1985-NOV. But there was no Word for Windows. In the meantime Windows 2.0 was released (1987-DEC).

"Windows 2.0 allowed application windows to overlap each other unlike its predecessor Windows 1.0, which could display only tiled windows." (wikipedia)

So if we now adapt history to WinRT:
WinRT 1.0 was released on 2012-OCT.
WinRT 2.0 will be released on 2014-NOV (with Windows 9.0 / WinNT 7.0).
Fully functional native Word RT 1.0 will be released on 2016-OCT.